Category size effects in recall: The roles of relational and individual item information.

Abstract

Memory for events varies as a function of the number of events in a given class, but previous research from organization theory did not succeed in establishing a consistent function relating memory and category size. We suggest that prior research can be systematized within a framework of relational and individual item processing. Relational processing refers to the encoding of similarities among events, and individual item, processing refers to encoding of distinctive information for each event. Assuming the importance of both types of information for precise recall and that the type of information encoded will depend on category size and the subject's attention to relational or distinctive features, predictions are derived concerning the interaction of orienting activity and category size. The predicted interaction was obtained in two experiments that demonstrated that small categories are better recalled following relational processing, and large categories are; better recalled following individual item processing. Additional dependent measures (clustering, category recall, items per category recall, and cued recall) provided highly consistent converging evidence for the proposed theoretical analysis. The general conclusion is that theories of memory must explain the paradoxical fact of the simultaneous importance of both similarity and difference.